Self-organization in dissipative structures: a thermodynamic theory for the emergence of prebiotic cells and their epigenetic evolution.

This paper presents a discussion on self-organization processes in dissipative structures, in order to highlight the general conditions for raising complexity and generate order. In particular, some concepts were introduced from non-equilibrium thermodynamics and from the Molecular Anamorphic Evolution Theory, especially concerning processes of matter randomization. Once a theoretical thermodynamics-based framework for understanding self-organizing systems had been presented, a spontaneous transition from macrostates richer in microstates to macrostates poorer in microstates was explained, as an attempt to point out the probable existing conditions at the formation of prebiotic structures. Closed systems, constrained by a lipid bilayer and with an internal water environment, were presented as cases of self-organization towards living systems. It was then highlighted that the origin of life depends on epigenetic and autopoietic processes, since metabolism plays a more relevant role than replication in making novelties emerge.

Distribution of arsenic in soils in a dump area in Tuscany (Scarlino, Follonica).

Arsenic (As) is ubiquitous in soils with an average concentration of 5-6 microg g(-1) in uncontaminated soils. Heavy metals (Pb, Cd, Cu, Zn, Cr, Fe and Al) were determined using flame or graphite-furnace atomic absorption. The mean concentrations (mg kg(-1)) of As (29-500 ppm), Fe (8%), Cu (76 ppm), Pb (52 ppm), Ni (90 ppm), Zn (258 ppm), Mg (1.56%), V (143 ppm), Cr (155 ppm), Cd (<2), Sb (0.29) and Hg (0.54) in fallow land soils are within the normal range. The mean As (470 ppm), Fe (10.57%) and Mg (1.67 ppm). We have evaluated how soil spectral response of pyrite and hematite is distributed in order to obtain the discrimination among these different soil compositions and their distribution along the dump area.

Recurrence plot analysis of nonstationary data: the understanding of curved patterns.

Recurrence plots of the calls of the Nomascus concolor (Western black crested gibbon) and Hylobates lar (White-handed gibbon) show characteristic circular, curved, and hyperbolic patterns superimposed to the main temporal scale of the signal. It is shown that these patterns are related to particular nonstationarities in the signal. Some of them can be reproduced by artificial signals like frequency modulated sinusoids and sinusoids with time divergent frequency. These modulations are too faint to be resolved by conventional time-frequency analysis with similar precision. Therefore, recurrence plots act as a magnifying glass for the detection of multiple temporal scales in slightly modulated signals. The detected phenomena in these acoustic signals can be explained in the biomechanical context by taking in account the role of the muscles controlling the vocal folds.

Effects of bioaccumulation of PCBs on biodiversity and distribution of fish in two creeks in east Tennessee (USA).

The Oak Ridge Reservation, established in Tennessee during World War II as a research, development and process facilities support for the Manhattan Project, released large quantities of organic, inorganic and radionuclear contaminants into the environment. Their effects are particularly evident in aquatic ecosystems, as chemical concentrations in water, and as a disease in biodiversity and species richness. East Fork Poplar Creek and its tributary, Bear Creek flow inside the Reservation and have highly degraded natural habitats, unsatisfactory water quality and impoverished biota. PCB concentrations exceed recommended criteria for aquatic life safety and appear as a primary cause of environment degradation and reduced species richness. An uptake model, FGETS (Food and Gill Exchange of Toxic Substances) was used to analyse fish biodiversity and distribution in the two streams in relation to bioaccumulation of PCB congeners 1254 and 1260. Bioaccumulation of the two polychlorinated biphenyls was estimated in four different species of fish common in Tennessee rivers and streams: Catostomus commersoni, Lepomis macrochirus, Cyprinus carpio and Micropterus salmoides to integrate the available set of data and to evaluate the entity of human impact on these escosystems.

Environmental aspects of pesticide use in Italian agriculture.

Pesticides used in agriculture accumulate in organisms and reach man through complex metabolic pathways. Accurate analysis of pesticides presence in each step of the food chain is necessary because of the high number of these substances, their potential toxicity and the presence of amplified toxic effects due to synergic interactions. In the same way it is necessary to evaluate the environmental effects of the whole pesticides cycle, from industrial production until final disposal of used containers and residuals. Furthermore recent introduction of new categories of chemicals which are not strictly classifiable as pesticides (photosynthetic activity stimulators, aesthetic aspect enhancers) and not yet sufficiently studied in their metabolic behaviour, increase the problem complexity. Complete studies about these complex problems and about the effects on ecosystems have not yet been carried out in Italy, due to ambiguous laws and regulations, inadequate data collection methods and decisional influence of the chemical industry on agriculture policy.

Virus-cell interactions: nuclear magnetic resonance behaviour of intracellular water.

The water proton NMR spin-lattice relaxation time if measured in HEp-2 cells in relation to the infection by different viruses (Poliovirus type 1, Coxsackievirus B-3, human Adenovirus, Measles virus, Respiratory Syncytial virus, Herpes simplex virus, subtype 1, and Vaccinia virus). The NMR properties of intracellular water allow the early detection and identification of viruses. A close relationship is shown between the NMR behavior and the mode of virus-cell interaction.

The water proton spin-lattice relaxation times in virus-infected cells.

The water proton spin-lattice relaxation times in HEp-2 cell cultures were determined immediately after 1 h of polio-virus adsorption. The shortening of the water T1 was closely related to the multiplicity of infection, allowing direct inspections of the virus--cell interaction since the first steps of the infectious cycle. Virus-induced structural and conformational changes of cell constituents were suggested to be detectable by NMR investigation of cell water.

[Selective broadening of NMR lines as a criterion in studying the interaction of Mn(II) with amino acids and peptides in D20]. / Izbiratel'noe ushirenie linii IaMR kak kriterii v izuchenii vzaimodeistviia Mn(II) s aminokislotami i peptidami v D20

A proton NMR study was carried out on complexes of Mn(II) with amino acids and peptides in aqueous solution. The theory, based on the Solomon-Bloembergen equations, was summarized and discussed. Different types of equilibria involving the anionic and zwittrionic forms of the amino acids were taken into account, together with the presence of outer- and inner-sphere species. The related correlation times were evaluated. Sarcosine, beta-alanine, threonine, tyrosine, valine, beta-alanine, proline, histidine and cystein complexes with Mn(II) were investigated on the basis of the NMR spectra. Moreover, diglycine and triglycine were studied in the presence of manganous ion at different pH value. The findings were discussed in terms of selective broadening of the NMR peaks and compared with data in the literature.

[pH dependence and EPR spectra of Fe-NO complexes with purines and pyrimidines]. / Zavisimost' ot pH i spektry EPR kompleksov Fe-NO s purinami i pirimidinami

Equilibria between different types of Fe(I)-dinitrosyl complexes with nucleobases in solution were studied by means of EPR spectroscopy. Computer simulation and 15NO isotopic substitution were used in order to make easier the interpretation of complicated EPR patterns. The pH dependence of the purine and pyrimidine complexes was investigated. Several EPR signals, under slow exchange conditions, were present in the range of pH values of biological significance. Four types of complexes were identified on the basis of the nuclear hyperfine structure: B' = where two purine molecules were bound to iron via N-7 in the imidazole ring; B'' = where two mercapto-base molecules were bound to iron via S-; B''' = where one mercapto-base molecule was bound to iron via S- and another via pyrimidine-nitrogen; B* = where two pyrimidine molecules were bound to iron via pyrimidine-nitrogen.

Co-ordination behaviour of nucleic acid bases against the Fe(I)(NO)-2 group in solution. I. Purines: ESR study.

The binding sites of purine bases in the presence of the Fe(I)(NO)-2 group were investigated on the basis of the nuclear hyperfine structure of the electron spin resonance spectra. Selective isotopic substitution with 15-NO was used to clarify co-ordindination. Coupling constants and different types of complexes were determined by means of computer-simulated ESR spectra. Comparison was made with the binding sites of nucleotides and it was concluded that N-7, in the imidazole ring, is the preferred binding site. A structure with two base molecules bonded to the iron atom was proposed. Finally 8-azaguanine, an antitumoral agent, was studied and the special behaviour of this antimetabolite was demonstrated in the biologically-interesting pH values.